2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/17550The effect of thermal fluctuations on a thin film magnetoresistive element has been calculated. The technique involves adding to the basic spin dynamics a general form of interaction with a thermal bath. For a general anisotropic magnetic system the resulting equation can be written as a Langevin equation for a harmonic oscillator. Our approach predicts two times smaller noise power at low frequencies than the conventional stochastic Landau-Lifshitz-Gilbert equation. It is shown that equivalent results can be obtained by introducing a tensor phenomenological damping term to the gyromagnetic dynamics driven by a thermal fluctuating field.Some minor changes with notations and comparison with Smith-Arnett resultMaterials ScienceStatistical Mechanicstext